diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
index efbdcd402cdf67..365756458bba30 100644
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -2,11 +2,11 @@ FROM docker.io/library/fedora:37
 
 ENV CC=clang
 
-ENV WASI_SDK_VERSION=19
+ENV WASI_SDK_VERSION=20
 ENV WASI_SDK_PATH=/opt/wasi-sdk
 
 ENV WASMTIME_HOME=/opt/wasmtime
-ENV WASMTIME_VERSION=7.0.0
+ENV WASMTIME_VERSION=18.0.2
 ENV WASMTIME_CPU_ARCH=x86_64
 
 RUN dnf -y --nodocs --setopt=install_weak_deps=False install /usr/bin/{blurb,clang,curl,git,ln,tar,xz} 'dnf-command(builddep)' && \
diff --git a/Misc/NEWS.d/next/Build/2024-03-04-12-43-42.gh-issue-116313.cLLb8S.rst b/Misc/NEWS.d/next/Build/2024-03-04-12-43-42.gh-issue-116313.cLLb8S.rst
new file mode 100644
index 00000000000000..61501549060024
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2024-03-04-12-43-42.gh-issue-116313.cLLb8S.rst
@@ -0,0 +1 @@
+Get WASI builds to work under wasmtime 18 w/ WASI 0.2/preview2 primitives.
diff --git a/Tools/wasm/wasm_build.py b/Tools/wasm/wasm_build.py
index c9947057a90754..f6e26296566551 100755
--- a/Tools/wasm/wasm_build.py
+++ b/Tools/wasm/wasm_build.py
@@ -316,8 +316,10 @@ def _check_wasi():
         # workaround for https://github.com/python/cpython/issues/95952
         "HOSTRUNNER": (
             "wasmtime run "
-            "--env PYTHONPATH=/{relbuilddir}/build/lib.wasi-wasm32-{version}:/Lib "
-            "--mapdir /::{srcdir} --"
+            "--wasm max-wasm-stack=8388608 "
+            "--wasi preview2 "
+            "--dir {srcdir}::/ "
+            "--env PYTHONPATH=/{relbuilddir}/build/lib.wasi-wasm32-{version}:/Lib"
         ),
         "PATH": [WASI_SDK_PATH / "bin", os.environ["PATH"]],
     },
diff --git a/configure b/configure
index e962a6aed12d27..938b6c6252406a 100755
--- a/configure
+++ b/configure
@@ -7720,7 +7720,7 @@ then :
 fi
      ;; #(
               WASI/*) :
-    HOSTRUNNER='wasmtime run --env PYTHONPATH=/$(shell realpath --relative-to $(abs_srcdir) $(abs_builddir))/$(shell cat pybuilddir.txt):/Lib --mapdir /::$(srcdir) --' ;; #(
+    HOSTRUNNER='wasmtime run --wasm max-wasm-stack=8388608 --wasi preview2 --env PYTHONPATH=/$(shell realpath --relative-to $(abs_srcdir) $(abs_builddir))/$(shell cat pybuilddir.txt):/Lib --dir $(srcdir)::/' ;; #(
   *) :
     HOSTRUNNER=''
    ;;
diff --git a/configure.ac b/configure.ac
index 384718db1f08d9..b3eaaa92464915 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1601,7 +1601,7 @@ then
     dnl TODO: support other WASI runtimes
     dnl wasmtime starts the proces with "/" as CWD. For OOT builds add the
     dnl directory containing _sysconfigdata to PYTHONPATH.
-    [WASI/*], [HOSTRUNNER='wasmtime run --env PYTHONPATH=/$(shell realpath --relative-to $(abs_srcdir) $(abs_builddir))/$(shell cat pybuilddir.txt):/Lib --mapdir /::$(srcdir) --'],
+    [WASI/*], [HOSTRUNNER='wasmtime run --wasm max-wasm-stack=8388608 --wasi preview2 --env PYTHONPATH=/$(shell realpath --relative-to $(abs_srcdir) $(abs_builddir))/$(shell cat pybuilddir.txt):/Lib --dir $(srcdir)::/'],
     [HOSTRUNNER='']
   )
 fi